I own both a CZ75B 9mm and a Steyr M40. I wanted a
compact carry gun and the Steyr had more features as far
as safety, primarily the manual safety inside the trigger
guard. I won't go into extolling the features of this
particular gun, and have no intentions of starting a
flamefest (I still may yet pick up a CZ100) but I will say
that mine has about 500 rounds through it so far and it
has yet to malfunction. The factory magazines have an
excellent fit and feed great. And the funky sights are
actually pretty fast, once you get used to looking at them.
As far as "buggy" units, (the gun wasn't introduced until '98 or so)
my net research prior to purchase seemed to
indicate you need to buy a gun built after August
of 2000, which means they would have already fixed the
initial extractor and trigger problems. Alternatively, look
for a serial number greater than 10,000 (mine is high
8000's but still had all the factory adjustments).
Dynamit-Nobel officially became Steyr's importer in April,
and theoretically the warranty should be supported by
them, but I really don't know and haven't read about
anyone having problems getting service one way or the
other. Just don't let anyone tell you that the M series
is an "orphan" any more than you would believe that CZ
is an "off" brand. I love both my pistols.
Ok, I will say this about the Steyr in .40. I fire full power
180 grain loads all the time, and my personal "perceived
recoil" is about the same as my CZ75 with 9mm 115's.
Some sort of alien technology, I guess.

The downside
is that to get better than 10 rounds capacity, you have to
cannibalize a mag from a Sigma, and the debate rages on
whether you will bring down the wrath of the ATF if you
choose to use a dremel to make it fit right. (I haven't)
Finally, I will say you need to pick which gun you feel
better shooting. It may be hard to find both of them
for rent at a local range. I don't think I answered your
request to give you a reason to *not* buy a Steyr, it's just
I went through the same thing after I found out that the
CZ compact carry was not going to happen. In my world,
the Steyr filled that void. For many other satisfied people,
the 100 is perfect. Sorry for rambling.
Jay